A database is a collection of stored data that is logically related and that is accessible by one or more users or applications. A popular type of database is the relational database management system (RDBMS), which includes relational tables, also referred to as relations, made up of rows and columns (also referred to as tuples and attributes). Each row represents an occurrence of an entity defined by a table, with an entity being a person, place, thing, or other object about which the table contains information.
One of the goals of a database management system is to optimize the performance of queries for access and manipulation of data stored in the database. Given a target environment, an optimal query plan is selected, with the optimal query plan being the one with the lowest cost (e.g., response time) as determined by an optimizer. The response time is the amount of time it takes to complete the execution of a query on a given system.
In massively parallel processing (MPP) systems, densely packed, rack based, multi-chassis computer systems require complex power cabling. During setup and maintenance, it is often difficult for technicians to detect improper cabling. If left undetected, an improperly cabled system may appear to be functioning normally but may lead to faulty shutdown sequencing in a power failure scenario which could lead to data corruption. Such systems are generally provided with user documentation or, at best, static images and help text for system component power configuration. Disadvantageously, such mechanisms are laborious and often lead to incorrect system configurations.